Grain-crushing roll



J. STEVEN Grain-Grushin 11.

No. 225,770.A Patented Mar. 23,1880.

UNITED STATES PATENT OFFICE.

' JOHN STEVENS, OF NEENAH, WISCONSIN.

GRAIN-CRUSHING ROLL.

SPECIFICATION forming part of Letters Patent No. 225,770, dated March 23, 1880.

Application led December 28, 1877. i

`or cylinders placed side by side in the same horizontal plane; and it consists in forming the rolls with spiral grooves running in the same direction on both rolls, so that they may cross each other on the opposed surfaces,and in gearing them together so as to revolve in opposite directions at different peripheral rates of speed, as hereinafter more particularly described.

The mill is employed for cracking wheat or other grain and operatin g on the same through the various stages of its reduction to Hour, and also for grinding and cleaning the bran.

In the accompanying drawings, forming part of this specication, Figure lis an end elevation, and Fig. 2 a plan view, of my improved grinding-mill.

The rolls A B (of chilled iron, steel, or other hard material) are of the same length and placed in the same horizontal plane, with their peripheries nearly in contact. 4They are geared to revolve at dii'erent peripheral rates of speed, and advisably in opposite directions, by means of the large spur-gear A' and small gear B', attached to the journals ofthe respective rolls on the outer side of the bearings G.

A series of spiral parallel grooves, a, is formed in the periphery of each roll. These grooves are light and fine, and are laid verynear together, but so as to leave appreciable plane surfaces between. They are laid in the same direction on both rolls, so that the grooves of one roll cross those of the other at the point where the rolls are most nearly in peripheral contact, whereby the latter may be run in varying adjustments and at differential speeds without any liability of the dress intermeshing and becoming injured. Since one roll revolves faster than the other, the grooves upon its surface may be said to shear across all the plane portions of and grooves in the opposing surface of the converse roll-an action admirably adapted to strip adhering starch and gluten from the bran.

In operation the plane portions of the rolls crush and atten the grain, leaving the husk and germ in the iiaky or discoidal condition most conducive to its effectual separation from the middlings and iiour. The grooves crossing each other on the contiguous surfaces of the rolls serve to seize and hold the material, to aid in its reduction and disintegration, and to receive the oury particles, but, being light and fine, do not pulverize the bran-a thing which it is the chief object of my invention to avoid.

The object of laying the grooves in the same direction upon each roll of the set is to cause them to cross each other and the intermediate plane portions upon contiguous surfaces, and it is evident that this may be sufficiently accomplished without laying them to the same pitch or inclination.

I claim as my invention- 1. In a grinding-mill, the combination of rolls geared to revolve at different peripheral rates of speed, and having a dress composed of fine parallel grooves laid near together, with appreciable plane surfaces between and so as to cros's cach other on the contiguous surfaces of the rolls.

2. In a grindingmill, the combination of rolls geared to revolve at different peripheral rates of speed, and having a dress composed of fine parallel grooves laid near together, with appreciable plane surfaces between and running in the same direction on each roll.

JOHN STEVENS.

Witnesses: v

J. L. CLEMENT, A; W. HART. 

